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Problems of Ascertainment of Congenital Anomalies

Published online by Cambridge University Press:  01 August 2014

J. Little*
Affiliation:
MRC Medical Sociology Unit, Institute of Medical Sociology, Aberdeen, Scotland
R. A. Carr-Hill
Affiliation:
MRC Medical Sociology Unit, Institute of Medical Sociology, Aberdeen, Scotland
*
Ecole de Santé Publique, Université Catholique de Louvain, Unité d'Epidémiologie, Epid 30.34, Clos Chapelle aux Champs 30, B-1200 Bruxelles, Belgium

Abstract

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Problems of ascertainment bedevil the investigation of the etiology of congenital anomalies in singletons and in multiple births by epidemiological methods. It is shown that the definition of the population of affected births is ambiguous and that the problem of tracing etiology is complicated by the systematic way in which anomalies may be missed at birth. The available methods of dealing with problems of ascertainment are reviewed. Methods of adjusting for possible bias of ascertainment of affected births, by fitting statistical models to data from several sources, have been employed in some previous studies. In these methods, it is assumed that there are no errors of diagnosis or of recording. However, it is shown that there may be discrepancies in recorded diagnoses between sources, rendering this assumption untenable. In these methods, it is also assumed that the model which is the best fit to the data on the ascertained cases in also the best model for the cases which were not ascertained. This assumption is tested indirectly in a retrospective analysis of data from Aberdeen and Belfast collected concurrently through routine recording systems. It is demonstrated that there was a social process in ascertainment which renders the methods of adjusting for bias of ascertainment at best very complicated and at worst inapplicable.

Type
Research Article
Copyright
Copyright © The International Society for Twin Studies 1984

References

REFERENCES

1.Alberman, ED, Creasy, MR (1977): Frequency of chromosomal abnormalities in miscarriages and perinatal deaths. J Med Genet 14:313315.Google Scholar
2.Baker, RJ, Nelder, JA (1978): The GLIM System, Release 3: Generalised Linear Interactive Modelling. Oxford: Numerical Algorithms Group.Google Scholar
3.Bishop, YMM, Fienberg, SE, Holland, PW (1975): Discrete Multivariate Analysis: Theory and Practice. Cambridge (Mass.): MIT Press.Google Scholar
4.Boué, J, Boué, A, Lazar, P (1975): Retrospective and prospective epidemiological studies of 1500 karyotyped spontaneous human abortions. Teratology 12:1126.Google Scholar
5.Carr, DH (1977): Chromosome studies in selected spontaneous abortions. Obstet Gynecol 37: 750754.Google Scholar
6.Hardy, J, Drage, JS, Jackson, EC (1979): The First Year of Life. Baltimore: Johns Hopkins U.P.Google Scholar
7.Hook, EB, Farina, MA, Hoff, MB (1977): Death certificate reports of cardiovascular disorders in children: comparison with diagnosis in a pediatric cardiology registry. J Chron Dis 30:383391.CrossRefGoogle Scholar
8.Lauritsen, JG (1976): Aetiology of spontaneous abortion. Acta Obstet Gynaecol Scand Suppl 52:129.Google ScholarPubMed
9.Little, J. (1983): Congenital anomalies in North-East Scotland and Northern Ireland: A comparative study. PhD thesis submitted, University of Aberdeen, Ch. 9.Google Scholar
10.Little, J. (1983): Congenital anomalies in North-East Scotland and Northern Ireland: A comparative study. PhD thesis submitted, University of Aberdeen, Ch. 10.Google Scholar
11.McIntosh, R, Merritt, KI, Richards, MR, Samuels, MH, Bellows, MT (1954): Incidence of congenital malformations: a study of 5964 pregnancies. Pediatrics 14:505522.Google Scholar
12.MacKenzie, IG, Wilson, JG (1981): Problems encountered in the early diagnosis and management of congenital dislocation of the hip. J Bone Joint Surg 63-B:3842.CrossRefGoogle ScholarPubMed
13.Morton, NE, Chung, CS, Mi, M-P (1967): Genetics of interacial crosses in Hawaii. Monographs in Human Genetics 3. Basel: Karger.Google Scholar
14.Nevin, NC, McDonald, JR, Walby, AL (1978): A comparison of neural tube defects identified by two independent routine recording systems for congenital malformations in Northern Ireland. Int J Epidemiol 7:319321.CrossRefGoogle ScholarPubMed
15.Porter, IH, Hook, EB (1980): Human Embryonic and Fetal Death. New York: Academic Press.Google Scholar
16.Registrar General (1970): Classification of Occupations. London: HMSO.Google Scholar
17.Roberts, CJ, Lowe, CR (1975): Where have all the conceptions gone? Lancet 1:498499.CrossRefGoogle Scholar
18.Stein, Z, Susser, M, Warburton, D, Wittes, J, Kline, J (1975): Spontaneous abortion as a screening device: the effect of foetal survival on the incidence of birth defects. Am J Epidemiol 102:275290.Google Scholar
19.Sweet, LK (1934): Mongoloid imbecility in the Mongolian races. J Pediatr 5: 352.Google Scholar
20.Vowles, M, Pethybridge, RJ, Brimblecombe, FSW (1975): Congenital malformations in Devon, their incidence, age and primary source of detection. In McLachlan, G (ed): Bridging in Health. London: Nuffield Provincial Hospitals Trust, p 201215.Google Scholar
21.Wittes, JT, Colton, T, Sidel, VW (1974): Capture-recapture methods for assessing the completeness of case ascertainment when using multiple information sources. J Chron Dis 27:2536.Google Scholar
22.World Health Organisation (1977): International Classification of Diseases: Manual of the International Classification of Diseases, Injuries and Causes of Death. Geneva: World Health Organisation.Google Scholar